out-of-round tube??

[PaulDoug]

Well I'll be giggered! I have been cussing my lathe because I have been having a real problem turning a pen blank. It has a wobble that I blamed my lathe for and was pretty upset. This morning I decided to play with it some more and I have now come to a new conclusion. I think the brass tube I glued in is slightly out-of-round. I have never experienced that before, but watiching the chuck, spindle they look smooth, but the blank has a definate wobble. It is worst at one end, so I tuned the blank around and the wobble moved with the blank. This is the most difficult blank I have ever turned. Don't know for sure what it is made of. It was a freeby. I have to take supper light cuts or it chips.

 

[PenMan1]

I got hold of a bad bunch of bushings once. They all came from the same place.
Since Jr. Gents wobbled, europeans wobbled, cigars wobbled, and not figuring to get 3 SETS of out of concentric bushings, it took FORVEVER to isolate the problem(s).

Your problem doesn't sound like bushings, but I now put every new set on the lathe and spin them at low speed. You would be surprised how many sets of bad bushings there are in the market place. It can never hurt to check bushings before using them.

It only takes a minute to check bushings and you know if you have a problem before you waste a unique blank.

Good luck finding the problem!

 

[seamus7227]

what about the mandrel?

 

[ed4copies]

If I am reading you correctly, that is not an unusual problem. Particularly with the larger pens, cap. The bit size that is designated can be quite a bit larger than the OD of the brass tube. So, it should come as no surprise that it gets closer to the wall (of the hole) on one end and the opposing opposite end. This results in a wobble.

NOW, if your LATHE is not DEAD ON--you can peel off the material from the tube on the side where your tube is farthest from the "wall" or "material" of the pen cap.

So, be careful and watch how thin the material is getting.

Also, measure the tubes with a caliper, drill the hole a little SMALL and sand it to the size you want (sandpaper mounted on a wood dowel). Minimizes the problem!

 

[PaulDoug]

Ed, Yes it was a sloppy fix for the tube. You probably nailed it. It turned out Okay and I just posted it. Was one of your freebie blanks, and a great blank also. I don't know what it is called but I think it looks great on the pen. It was a challenge for me to turn but worht it. I just posted a picture a few minutes ago "PSI Vertex II